USB extension cable

Discussion in 'The Projects Forum' started by gyp, May 12, 2011.

  1. gyp

    Thread Starter New Member

    May 12, 2011
    2
    0
    I want to put a webcam out in the garden, is there a limit to the length of a USB cable, does is loose power or performance?

    Thanks
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    http://www.usb.org/about/faq/ans5

    16feet 5inches without hubs.

    Consider running power, then using a wireless webcam to communicate back to the house. A CANTENNA could increase your distance to a 100 feet or more if properly built.
     
  3. CDRIVE

    Senior Member

    Jul 1, 2008
    2,223
    99
  4. DumboFixer

    Active Member

    Feb 10, 2009
    219
    34
    or 5M (aka 500cm)
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,103
    3,038
    You've heard what the spec is. There's also the practical reality, which MIGHT allow a length of double the spec, or not. And on that ragged edge, cable and connector quality might matter.

    Power loss is trivial unless the camera is a high power draw. And it would be relatively easier to get power to the camera if you needed to use something besides USB to power it. I believe what you will lose with increasing length is bandwidth, or high frequency performance. Things like cable capacitance cause a slowdown. If the camera and USB driver depend on high frequency, you may not get much past the spec distance. But if they're "tolerant" of low bandwidth, they might work. No way to know except to try.

    I wouldn't expect most USB cables to last long outdoors. They're not made for it. Which raises another idea: You could run a longer distance using a heavier-duty, 4-conductor cable with USB connectors grafted to the ends.
     
  6. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Well SuRE, if you S-TRE-TCH the cable the extra .115" ;)

    @wayneh, you can NO-DOUBT run them longer. The USB standard requires FULL-SPEED at 16feet 5inches.

    So, you may have to change baud rate on a 50ft cable.


    What about USB to cat-5 adapters on each end?
     
Loading...